Shock absorber with movement limiting stop for rotary printing press cylinders



y 8, 1969 H. J. SEEL. ETAL 3,453,955

SHOCK ABSORBER WITH MOVEMENT LIMITING STOP FOR ROTARY PRINTING PRESS CYLINDERS Filed Oct. 20, 1965 Sheet or 2 IN VENTORS HOWARD J. SEEL BY ROBERT J. ANDERSON ATTORNEYS y 1969 H. J. SEEL ETAL 3,453,955

' SHOCK ABSORBER WITH MOVEMENT LIMITING STOP FOR ROTARY PRINTING PRESS CYLINDERS 5 Sheet 2 of 2 Filed Oct. 20, 196

1N VENTORS HOWARD J. SEEL BY ROBERT J. ANDERSON ATTORNEYS H United States Patent US. Cl. 101-216 30 Claims ABSTRACT OF THE DISCLOSURE An improved printing press having cylinders which cooperate in a pressure relationship along a line of engagement with at least one of the cylinders having an axially extending gap in the periphery thereof with clamp means located in the gap for positioning the material engaging an outer surface of the cylinder during operation of the printing press. The one cylinder includes a shock absorbing means located radially inwardly of the material positioned by the clamp means for absorbing shock and dampening movement of the cylinders produced in response to a change of pressure as the gap passes the line of engagement. Stop means in provided for opposing move ment of the shock absorbing means to limit yielding thereof.

The present invention relates to rotary machines having cylinders for performing an operation on sheet-like material passing through the machine and more particularly to printing presses and particularly lithographic printing presses.

Offset lithographic printing presses have a plate cylinder, a blanket cylinder, and an impression cylinder with a printing nip being formed between the blanket and impression cylinders and the plate cylinder running in engagement with the blanket cylinder to form the image to be printed thereon. In offset printing presses, the periphery of the blanket cylinder will have a gap and means in the gap for attaching the blanket to the blanket cylinder. Similarly, the plate cylinder will have a gap which registers with the gap in the blanket cylinder as the cylinders rotate and means in the gap for attaching the plate to the plate cylinder and in sheet fed lithogrphic printing presses, the impression cylinder also includes a gap in which sheet grippers are located for gripping the leading edge of a sheet to be carried through the printing nip.

In an offset press a printing pressure exists between the blanket cylinder and the impression cylinder when a sheet is being printed at the nip. While the blanket cylinder has a blanket thereon which might be described as relatively soft or yieldable relative to the surface of the impression cylinder, the blanket must be firm enough to maintain this printing pressure to produce quality printing. It will be recognized by those skilled in the art that this printing pressure is relieved and re-established as the leading and trailing edges of the gaps of the blanket cylinder pass the print line in succession.

The abrupt relieving and establishing of pressure as the gaps pass each other may cause shock loads on the cylinders resulting in a bouncing or lateral vibration of the plate cylinder as the pressure is established or relieved and this can result in print disturbances on the printed sheet. Moreover, the shock in certain presses tends to cause backlash movement of the blanket cylinder to slow the cylinder relative to the plate cylinder. At the time pressure is being established or relieved at the printing nip, the periphery of the plate cylinder is in engagement with the blanket and is transferring the image on the plate to the blanket. .Any bouncing or movement ice of the blanket cylinder as the printing pressure is re lieved or established may affect the image which is transferred from the plate to the blanket which in turn will be reflected in the final print. Similarly, at the time the leading and trailing edges of the gaps in the blanket and plate cylinders pass each other to alternately relieve and establish an image transferring relationship therebetween, printing will normally be occurring at the printing nip and any bouncing of the blanket cylinder due to relieving or establishing the pressure relationship between the plate cylinder and the blanket cylinder will be reflected in the quality of the printed sheet.

An important object of the present invention is the provision of a new and improved rotary machine having cooperating, rotating cylinders which operate in a pressure relationship, there being a peripheral gap in at least one cylinder and the cylinders being so constructed and arranged that the pressure relationship between the cylinders is gradually changed by movement of a resiliently defiectable surface adjacent an edge of the gap and wherein the extent of movement of the resiliently defiectable surface is limited to a predetermined maximum.

Another object of the present invention is to provide a new and improved rotary machine having cooperating cylinders which operate in a pressure relationship and in which at least one of the cylinders has a gap therein and a resiliently deflectable surface adjacent at least one edge of the gap to cause the pressure relationship therebetween to vary progressively between minimum and maximum operating values as the edge passes the line of engagement of the cylinders. and wherein an adjustable stop is provided to limit the extent of the deflection of the resiliently deflectable surface.

Another object is the provision of a new and improved printing press having cooperating cylinders which operate in a pressure relationship and form a printing couple and have gaps therein which register with each other as the cylinders are rotated, and in which at least one of the cylinders has a resiliently defiectable surface adjacent at least one edge of the gap to cause the pressure relationship to be progressively established and relieved as the gaps pass into and out of registry and means for limiting deflection of the resiliently deflectable surface including a resilient material cast into the last mentioned cylinder.

Another object is the provision of a new and improved printing press including a rotating cylinder having a gap therein and a Wedge of resiliently deflectable material supported by a rigid surface on the cylinder and forming a deflectable surface on the cylinder adjacent an edge of the gap.

Another object of the invention is the provision of a new and improved printing press in accordance with the next preceding object wherein the resilient material is interposed between the resiliently deflectable surface and a rigid member which forms a positive stop against deflection of the surface.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof and the accompanying drawings which form a part of the specification and wherein:

FIG. 1 is a diagrammatical illustration of a printing press embodying the present invention;

FIG. 2 is an enlarged fragmentary elevational view of a portion of the printing press of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view of a portion of a modified form of the printing press of FIG.

FIG. 4 is an enlarged fragmentary sectional view of a portion of a modified form of the printing press of FIG.

; and

FIG. 5 is an enlarged fragmentary sectional view of a portion of a modified form of the printing press of FIG. 1

The present invention is susceptible of use in various types of rotary machines wherein at least one of the cooperating rotating cylinders which Operate in pressure relationship has a gap in the periphery thereof, but is particularly useful in a printing press, such as an offset lithographic printing press, where the establishment and reestablishment of pressure as a gap passes the print line may cause print disturbances and the like.

Referring to the drawings, FIG. 1 shows an offset lithographic printing press which embodies the present invention. As illustrated therein the lithographic printing press includes a plate cylinder 10, a blanket cylinder 11, and an impression cylinder 12. These cylinders are in engagement as illustrated and the plate cylinder rotates in a counterclockwise direction, the blanket cylinder in a clockwise direction and the impression cylinder in a counterclockwise direction, as viewed in FIG. 1, so that the peripheries of the cylinders move in the same direction at the nips between each of the cylinders. The printing plate 13 with the image to be printed is mounted on the plate cylinder by plate clamps which are located in a gap 14 in the periphery of the cylinder. The plate clamps for mounting a plate on the plate cylinder are conventional and therefore have not been shown since the clamps per se are not necessary for an understanding of the present invention. The printing plate has a dampening fluid applied thereto by dampening rolls 15 which form part of a dampening mechanism not shown in detail. Ink is applied to the plate by ink rolls 16 which form a part of an inking mechanism also not shown in detail. The dampeners 15 and the inker 16 may be of any suitable, conventional form.

After ink is applied to the plate cylinder 10, the image to be printed is transferred to a conventional blanket 17 mounted on the blanket cylinder 11. The blanket 17 is held on cylinder 11 by clamps 18 which are mounted in a gap 20 in the periphery of the blanket cylinder 11. The gap 20 is of the same angular extent as the gap 15 in the plate cylinder 10 and registers therewith as the cylinders are rotated. The image on the blanket cylinder 11 is printed onto a sheet 21 on the impression cylinder 12 as the blanket cylinder rotates past a printing nip formed by the blanket cylinder 11 and the impression cylinder 12. The sheet to be printed is carried through the printing nip by grippers 22 on the impression cylinder 12. The sheet is fed to the impression cylinder 12 by any conventional feeding mechanism and the impression cylinder 12 may receive the sheet from a feed cylinder 24. The grippers 22 are disposed in a gap 23 in the impression cylinder 12 with the gap 23 extending for the same angular extent about the impression cylinder as the gaps 14 and 20 extend about the peripheries of the plate cylinder and blanket cylinder, respectively. The grippers 22 carry the sheet to be printed through the printing nip and release the sheet on the outgoing side of the printing nip to another transfer unit for delivery to a subsequent unit or a delivery mechanism. The transfer cylinder and associated mechanisms are not shown in the drawings but may be of any suitable, conventional construction.

The blanket cylinder 11 and the impression cylinder 12 operate in a pressure relationship when the peripheries of the cylinders are in engagement with each other at the printing line so as to provide the necessary printing pressure for obtaining a quality print. The printing pressure between the cylinder peripheries exists even though no sheet is in the nip and is increased somewhat by the presence of a sheet. It will be appreciated that when the gaps in the blanket cylinder and the impression cylinder rotate so that the leading edges 25 and 26 of the gaps 20 and 23 pass each other, the pressure between the blanket 17 on the cylinder 11 and the surface of the impression cylinder 12 is suddenly relieved as the gaps 20 and 23 come into registry with each other. This sudden release of pressure produces a shock which tends to cause a bouncing or lateral vibration of the blanket cylinder 11. A similar bouncing of the blanket cylinder 11 occurs when the pressure relationship between the cylinders is re-established as the trailing edges 30 and 31 of the gaps pass each other since the operating pressure between the cylinders varies from minimum to maximum as the trailing edges of the gaps meet each other.

Similarly, the blanket 17 on the blanket cylinder 11 has a pressure relationship with the plate 13 on the plate cylinder 10 and when the gaps 14 and 20 of these cylinders meet each other at the nip of the two cylinders, this pressure is relieved. As the gaps pass each other and the cylinders are re-engaged and the pressure between them is reestablished. It will be understood by those skilled in the art that the cylinders in the illustrated machine may have the bearers conventionally used at the outer ends thereof with the bearers on the cooperating cylinders being loaded against each other. The pressure established by the engagement of the peripheral surfaces of the cylinders acts against this loading.

It will be noted that when the pressure is relieved at the print line between the blanket cylinder 11 and the impression cylinder 12, the plate cylinder is normally in a position where an image is being transferred from the plate to the blanket 17 on the blanket cylinder and any movement of the blanket cylinder relative to the plate cylinder at the line of engagement therebetween may cause a disturbance in the image being transferred which Will be reflected in the printed sheet. Similarly when the gap in the blanket cylinder meets and passes the gap in the plate cylinder, the blanket is in the process of transferring an image to a sheet on the impression cylinder and any disturbance caused by the establishment or relieving of the pressure between the plate cylinder and the blanket cylinder may affect the print being made at the print line.

In the illustrated press, each of the cylinders has shock absorbing means adjacent the edges of the gap to minimize shock disturbances. In the preferred embodiment, the cylinders are all constructed so that the pressure as the edges of the gaps therein pass the line of engagement of a cooperating cylinder is progressively changed over an appreciable angular movement of the cylinder to minimize any tendency of the cylinders to bounce due to shock accompanying the pressure change. For convenience of illustration a blanket cylinder assembly having a shock absorbing means operatively associated therewith is shown and will be described in detail.

FIG. 2 illustrates the relationship between the blanket clamps, blanket and cylinder when assembled. Blanket 17 extends about the blanket cylinder 11 and is connected at its ends to clamp means 18 located in cylinder gap 20.

The ends of the blanket 17 carry blanket bars a and 6011 which are connected thereto by means of screws and which compressively engage the blanket material. Bars 60a and 6912 include beveled side surfaces 62a and 62b which cooperate with similarly slanted side surfaces of grooves 63a, 63b in the clamp means 18a, 18b, respectively, to form a dovetail connection between the blanket and the clamp means.

Blanket 17 is longer than the circumferential extent of the blanket cylinder 11 upon which it is assembled. The ends of the blanket are placed in the grooves to form the aforementioned dovetail connection between the blanket and the clamp means so that the blanket is loosely supported on the cylinder. The clamp member or blanket reel 18a includes a rotatable shaft 64 having the groove 63a therein which extends axially therealong and forms the aforementioned dovetail connection with blanket bar 60. Shaft 64 is rotated in a counterclockwise direction to tighten the blanket about the periphery of the cylinder. A ratchet mechanism of conventional design, which is not shown, is connected to the shaft and is operative to prevent a clockwise rotation of the shaft and loosening of the blanket after the blanket has been tightened. Shaft 64 is rotatably supported in the gap by a suitable support member 65 of conventional construction.

Clamp member 18b is connected to the other end of the blanket, and includes a fixed support member 66 and a movable support member 67 which is slidably supported on the fixed member. Movable member 67 is connected to the blanket bar by means of a dovetail joint as previously described. After the blanket has been tightened by the rotation of the shaft 64 of clamp member 18a further adjustment in the wrap of the blanket may be made by the clamp member 18b. The movable support member 67 may be moved with respect to the side 70 of the gap by rotation of adjustment screws 71 in the movable member. It should be understood that screws 71 are spaced along clamp member 18b and that the screws and mechanism associated therewith are identical. For this reason only one of the adjustment screws and its associated parts is shown and described herein. The screw 71 is adapted to abut one end of a rod 72 which is slidable in the movable member. The other end of the rod abuts the side 70 of the gap so that upon clockwise rotation of the screw 71 the slidable member abuts the side of the gap and forces the movable member away from the side of the gap to further tension a portion of the blanket to eliminate angular misalignment of the blanket on the cylinder. After the blanket has been tensioned to remove any blanket misalignment, a stud 72 extending through a slot 73 on the movable member and threaded into the fixed member 66 is tightened to fix the position of the movable support member 67 with respect to the fixed support member 66.

The structure for progressively relieving and establishing the pressure relationship between the cylinders is substantially the same in each cyinder and for convenience will be described hereinafter in reference to the blanket cylinder. The gap 20 of the blanket cylinder 11 has a leading side and a trailing side 26 which extend inwardly from the periphery of the cylinder toward the bottom of the gap 20. The side 25 of the gap is cut out to form an undercut 27 which extends in the direction of the circumference of the cylinder to undercut the periphery of the cylinder adjacent the leading edge 20a of the gap so that the portion 28 of the cylinder periphery adjacent the leading edge of the gap is formed on a resiliently deflectable or cantilevered projection 29. It will be understood that the undercut 27 preferably extends the full axial length of the cylinder and this resiliently deflectable projection is preferably of uniform cross section along the length of the cylinder. The defiectability of the projection 29 is such that adequate printing pressure is established immediately after the trailing edge of the gap passes the line of engagement.

In the preferred and illustrated embodiment, the deflectability of the cantilivered projection 29 is limited by a stop 30. However, it will be appreciated that instead of using a stop 30, the undercut 27 could be made so that the inner side 27a of the undercut acts as a stop for the deflectable projection 29.

The trailing side 70 of the gap is also cut out to form an undercut 32 which is similar to and corresponds with the undercut 27 to provide a deflectable cantilevered rojection 33 which extends along the trailing edge of the gap. As in the case of the deflectable projection 29, a stop 34 may be provided to limit the deflectability of the cantilevered projection 33.

In the illustrated embodiment, the stops 30, 34 are shown as pieces which are held in position in the undercuts 27, 32, respectively, by screws 35, The stops may be adjusted in height by loosening the screws 35 and inserting a shim under the stop member. Such a shim is indicated under the stop member by the reference numeral 36.

The undercut 32 may, alternatively, be filled with a resiliently yieldable material which will deform but act to limit the deflection of the cantilevered projection 33 of the blanket cylinder. Such a construction is illustrated in FIG. 3 and the resiliently yieldable material 39 is shown as filling an undercut 40 cut out of a side of a cylinder gap similar to the undercut 32. A rigid dam member 41 is located adjacent the open end of the undercut and forms a dam so that the resiliently yieldable material can be cast into the space. Also the top 42 of the dam member may provide a stop, if desired, to limit movement of the deflectable projection.

FIG. 4 illustrates an alternative construction for making an adjustable stop. In accordance with FIG. 4, a cylinder gap 43 is cut away at its side to provide a recess 44 in which an alloy steel cylinder insert 45 is positioned. The insert 44 is connected to the cylinder by conventional connecting means which has not been shown in the drawing. The insert includes an undercut 50 corresponding to the undercut 32 of the first described embodiment, but the undercut 50 has an inclined surface 50a, remote from the peripheral portion, which supports a redraw wedge block 51. The wedge block is moved up and down the inclined surface 50a by rotation of adjusting screws 55 to adjust the top 51a of the wedge block toward and away from the deflectable projection 53 of the cylinder. Wedge block 51 has a depending portion 52 which extends into groove 54 opening into the inclined surface 50a and into which adjusting screws 55, of which one is shown in the drawings, are threaded. The adjusting screws 55 are positioned in an apertured plate 56 which is connected to the cylinder by conventional means, not shown. Screws 55 are loosely received in plate 56 and means such as spring 57 are employed to prevent the screws from backing out of the plate.

It will be seen from FIG. 2 that the material of the blanket is relatively thin and as described, is under tension on the blanket cylinder. While the material of the blanket is relatively soft as compared with the material of the cylinder, the material is of uniform thickness at its ends and does not provide a shock absorbing effect. Moreover, the material must offer suflicient rigidity to maintain print pressure. The sides of gap 20 of the illustrated blanket cylinder have been undercut to provide resiliently deflectable cantilevered projections, as described previously, to eliminate bouncing of the blanket cylinder and its cooperating cylinders as the gaps pass while the cylinders are rotating.

The resiliently deflectable or cantilevered projections described above, extend along the cylinder from the adjacent side of the gap. The deflectability of these projections decreases circumferentially from the sides of the gap in a manner characteristic of cantilevered structures so that the pressure relationship between the cylinders is gradually varied between limiting values during an appreciable angular movement of the cylinder rather than abruptly at substantially the instant that the edges of the gaps meet at the line of engagement of the cylinders.

FIG. 5 illustrates a modified cylinder wherein the cylinder includes a cutout portion 81 adjacent the gap 82. The cutout portion 81 extends axially along the gap and contains a wedge 83 formed from a resiliently deflectable material and which is connected to the cylinder in any convenient manner. The wedge 33 deflects to absorb the changes in the pressure relationship between the cylinders as they rotate, and the surface of the cutout portion 81 limits the extent of this deflection. As illustrated, the defiectabi'lity of the wedge portion decreases circumferentially from the gap 83 so that the pressure relationship between the cooperating. cylinders is progressively varied between limiting values over an appreciable portion of a revolution of the cylinder.

Having described our invention, we claim:

1. In a printing press, a pair of cooperating rotating cylinders operating in pressure relationship, one of said cylinders having an axially extending gap in the periphery thereof which cyclically causes the pressure between the peripheries of the cylinders to change as the cylinders rotate, said one of said cylinders including a wedge of resiliently deflectable elastorneric material adjacent an edge of said gap, said wedge of elastomeric material providing a resiliently deflectable surface por- 7 tion on said cylinder adjacent said gap, and a rigid surface on said cylinder supporting said wedge of elastomeric material, the defiectability of said surface portion progressively decreasing circumferentially from said gap.

2. A printing press of claim 1 wherein said rigid surface provides a positive stop for limiting deflection of said surface.

3. In a rotary machine having cooperating cylinders which cooperate in pressure relationship along a line of engagement with at least one of said cylinders having an axially extending gap in the periphery thereof having trailing and leading sides, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said one cylinder having resiliently yieldable shock absorbing means adjacent a first side of said gap for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of the gap passes said line, stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a rigidly supported stop surface detachably connected to said one cylinder, and means associated with said rigidly supported stop surface for adjusting the position of said stop surface relative to said shock absorbing means to vary the extent of yielding of said shock absorbing means.

4. In a printing press, a pair of cooperating rotating cylinders operating in pressure relationship, one of said cylinders having an axially extending gap in the periphery thereof which cyclically causes the pressure between the peripheries of the cylinders to change as the cylinders rotate, said one of said cylinders having a surface portion adjacent said gap formed on a circumferentially cantilevered part of said cylinder and defining an edge thereof which is resiliently defiectable, the defiectability of said portion progressively decreasing circumferentially from said gap, stop means between said cantilevered part and said cylinder for limiting the extent of deflection of said cantilevered part to a predetermined maximum amount, and means for adjusting the position of said stop means relative to said cantilevered part.

5. In a printing press, a pair of cooperating rotating cylinders operating in pressure relationship, one of said cylinders having an axially extending gap in the periphery thereof which cyclically causes the pressure between the peripheries of the cylinders to change as the cylinders rotate, said one of said cylinders having a surface portion adjacent said gap formed on a circumferentially cantilevered part of said cylinder and defining an edge thereof which is resiliently defiectable, the defiectability of said portion progressively decreasing circumferentially from said gap, and stop means between said cantilevered part and said cylinder for limiting the extent of deflection of said cantilevered part to a predetermined maximum amount, said stop means including a body of resiliently compressible material and a rigidly supported stop member projecting into said resiliently compressible material for providing a positive stop against deflection of said cantilevered part.

6. In a printing press comprising one cylinder having a hard, crush resistant outer surface for supporting a printing element having leading and trailing portions during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line with said one cylinder, the pressure relationship between said cylinders changing substantially as the leading side of the gap passes the line of engagement of said cylinders, said one cylinder including shock absorbing means adjacent to the trailing side of said gap radially inwardly of the printing element and providing a leading portion of the hard outer surface, said shock absorbing means terminating within said cylinder beneath the leading end portion of the printing element for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said trailing side of said gap passes said line during operation of said printing press and stop means located within said cylinder radially inwardly of said shock absorbing means for opposing movement of said shock absorbing means to limit yielding thereof.

7. A printing press as set forth in claim 6 wherein said shock absorbing means includes a resiliently yieldable member and said stop means includes a rigidly supported stop member located within said one cylinder radially inwardly of said yieldable member.

8. In a printing press comprising an impression cylinder having a hard, crush resistant outer surface for at least partially supporting ink receiving material having leading and trailing portions during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a co operating print cylinder operating along a line with said impression cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said im pression cylinder including shock absorbing means adjacent to the trailing side of said gap and located radially inwardly of the ink receiving material and providing a leading portion of the hard outer surface, said shock absorbing means terminating within said impression cylinder in a circumferential distance from the trailing side of said gap which is no greater than the extent of said leading portion of said ink receiving material for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press and stop means located Within said cylinder radially inwardly of said shock absorbing means for 0pposing movement of said shock absorbing means to limit yielding thereof.

9. A printing press as set forth in claim 8 wherein said shock absorbing means includes a resiliently yieldable member and said stop means includes a rigidly supported stop member located within said one cylinder radially inwardly of said yieldable member.

10. In a printing press, a pair of cooperating rotating cylinders operating in pressure relationship, at least one of said cylinders defining an outer surface for supporting a printing or sheet element during a printing opera tion, said one of said cylinders having an axially extending gap in the periphery thereof which causes the pressure between the peripheries of the cylinders to change as the cylinders rotate, said outer surface of said one of said cylinders having a surface portion adjacent said gap formed on a circumferentially cantilevered part of said one cylinder and defining an edge thereof which is resiliently defiectable and located radially inwardly of said element for absorbing shock and dampening movement of said cylinders produced in response to the change in pressure, and stop means between said cantilevered part and a portion of said one cylinder radially inwardly of said cantilevered part for limiting the extent of defiection of said cantilevered part to a predetermined maximum amount.

11. In a printing press as set forth in claim 10 where in said stop means includes an axially extending member located radially inwardly of said cantilevered part and supported by said portion of said one cylinder.

12. In a printing press as set forth in claim 11 wherein said stop means further includes shim means associated with said member for at least partially determining said predetermined maximum amount of deflection.

13. In a printing press as set forth in claim 10 wherein said stop means includes a body of elastomeric material located radially inwardly of said cantilevered part and supported by said portion of said one cylinder.

14. In a rotary printing press having cooperating nip forming cylinders, at least one of said cylinders defining an outer support surface for supporting a printing or sheet element during a printing operation, said surface extending circumferentially about the cylinder and having trailing and leading surface portions each lying adjacent to an axial gap in the periphery of said one cylinder and a surface portion intermediate said trailing and leading surface portions, said intermediate surface portion being radially inwardly unyieldable, at least one of said trailing and leading surface portions being deflectable radially inwardly, means for absorbing shock and maintaining print pressure as said radially inwardly deflectable one of said trailing and leading surface portions passes through the nip comprising yieldable means providing said one surface portion and progressively increasing resistance to the yielding thereof in response to a given load proceeding from the gap adjacent said one of said surface portions toward said intermediate surface portion, and stop means located radially inwardly of said one of said trailing and leading surface portions for limiting inward deflection thereof.

15. In a printing press, a cylinder as defined in claim 14 wherein said yieldable means comprises a member extending circumferentially from and connected to said rigid unyieldable portion, said member having an underside facing generally radially inwardly of the cylinder, and said stop means comprises means for engaging the underside of said member to limit the deflectability thereof.

16. In a printing press as set forth in claim 15 wherein said means for engaging the underside of said member comprises an axially extending bar.

17. In a printing press as set forth in claim 16 wherein said means for engaging the underside of said member further comprises at least one axially extending shim which cooperates with said bar to at least partially control the deflectability of said member.

18. In a printing press as set forth in claim 15 wherein said means for engaging the underside of said member comprises a body of elastomeric material.

19. In a printing press comprising a plate cylinder for holding a printing plate during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said plate cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said plate cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the printing plate mounted on said plate cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a rigidly supported stop surface on said plate cylinder and detachably connected to said plate cylinder, and means associated with said rigidly supported stop surface for adjusting the position of said stop surface relative to said shock absorbing means to vary the extent of yielding of said shock absorbing means.

20. In a printing press comprising a plate cylinder for holding a printing plate during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said plate cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said plate cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the printing plate mounted on said plate cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing mean to limit yield- 10 ing thereof, said stop means including a body of elastomeric material connected to said plate cylinder.

21. In a printing press comprising a plate cylinder for holding a printing plate during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said plate cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said plate cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the printing plate mounted on said plate cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said shock absorbing means including a resiliently yieldable means extending axially along said plate cylinder at said first side of said gap and said stop means includes a body of elastomeric material connected to said plate cylinder and located between said resiliently yieldable means and a rigidly supported surface to limit deflection of said resiliently yieldable means.

22. In a printing press comprising an impression cylinder for at least partially supporting ink receiving material during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said impression cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said impression cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the ink receiving material which is at least partially supported by said impression cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a rigidly supported stop surface on said impression cylinder and detachably connected to said impression cylinder, and means associated with said rigidly supported stop surface for adjusting the position of said stop surface relative to said shock absorbing means to vary the extent of yielding of said shock absorbing means.

23. In a printing press comprising an impression cylinder for at least partially supporting ink receiving material during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said impression cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said impression cylinder including shock absorbing means adjacent. to a first side of said gap and located radially inwardly of the ink receiving material which is at least partially supported by said impression cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a body of elastomeric material connected to said impression cylinder.

24. In a printing press comprising an impression cylinder for at least partially supporting ink receiving material during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said impression cylinder, the

pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said impression cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the ink receiving material which is at least partially supported by said impression cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said shock absorbing means including a resiliently yieldable means extending axially along said impression cylinder at said first side of said gap and said stop means includes a body of elastomeric material connected to said impression cylinder and located between said resiliently yieldable means and a rigidly supported surface to limit deflection of said resiliently yieldable means.

25. In a printing press comprising cooperating plate, impression and blanket cylinders, at least one of said cylinders operating along a line of engagement with a cooperating one of said cylinders and having an axially extending gap in its periphery, clamp means located in said gap for use in positioning material engaging an outer surface of said one cylinder during operation of said printing press, the pressure relationship between said one cylinder on its cooperating cylinder changing substantially as an edge of the gap passes the line of engagement of the cylinders, said one cylinder including shock absorbing means adjacent to a first side of said gap and said clamp means and located radially inwardly of the material engaging said outer surface of said one cylinder for absorbing shock and dampening movement of said one cylinder produced in response to a change in pressure as said first side of said gap passes said line of engagement, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a rigidly supported stop surface on said one cylinder and is detachably connected to said one cylinder, and means associated with said rigidly supported stop surface for adjusting the position of said stop surface relative to said shock absorbing means to vary the extent of yielding of said shock absorbing means.

26. In a printing press comprising cooperating plate, impression and blanket cylinders, at least one of said cylinders operating along a line of engagement with a cooperating one of said cylinders and having an axially extending gap in its periphery, clamp means located in said gap for use in positioning material engaging an outer surface of said one cylinder during operation of said printing press, the pressure relationship between said one cylinder on its cooperating cylinder changing substantially as an edge of the gap passes the line of engagement of the cylinders, said one cylinder including shock absorbing means adjacent to a first side of said gap and said clamp means and located radially inwardly of the material engaging said outer surface of said one cylinder for absorbing shock and dampening movement of said one cylinder produced in response to a change in pressure as said first side of said gap passes said line of engagement, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a body of elastomeric material connected to said one cylinder.

27. In a printing press comprising cooperating plate, impression and blanket cylinders, at least one of said cylinders operating along a line of engagement with a cooperating one of said cylinders and having an axially extending gap in its periphery, clamp means located in said gap for use in positioning material engaging an outer surface of said one cylinder during operation of said printing press, the pressure relationship between said one cylinder on its cooperating cylinder changing substantially as an edge of the gap passes the line of engagement of the cylinders, said one cylinder including shock absorbing means adjacent to a first side of said gap and said clamp means and located radially inwardly of the material engaging said outer surface of said one cylinder for absorbing shock and dampening movement of said one cylinder produced in response to a change in pressure as said first side of said gap passes said line of engagement, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said shock absorbing means including a resiliently yieldable member extending along said one cylinder from said gap and said stop means includes a body of elastomeric material connected to said one cylinder and located between said resiliently yieldable member and a rigidly supported surface to limit deflection of said resiliently yieldable member.

28. In a printing press comprising a blanket cylinder for holding a blanket member during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said blanket cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said blanket cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the blanket member mounted on said blanket cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line of engagement during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a rigidly supported stop surface on said blanket cylinder and detachably connected to said blanket cylinder, and means associated with said rigidly supported stop surface for adjusting the position of said stop surface relative to said shock absorbing means to vary the extent of yielding of said shock absorbing means.

29. In a printing press comprising a blanket cylinder for holding a blanket member during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said blanket cylinder, the pressure relationship between said cylinders changing substantially as an edge Of the gap passes the line of engagement of said cylinders, said blanket cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the blanket member mounted on said blanket cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line of engagement during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said stop means including a body of elastomeric material connected to said blanket cylinder.

30. In a printing press comprising a blanket cylinder for holding a blanket member during operation of said printing press and having an axially extending gap in the periphery thereof having trailing and leading sides, a cooperating cylinder operating along a line of engagement with said blanket cylinder, the pressure relationship between said cylinders changing substantially as an edge of the gap passes the line of engagement of said cylinders, said blanket cylinder including shock absorbing means adjacent to a first side of said gap and located radially inwardly of the blanket member mounted on said blanket cylinder for absorbing shock and dampening movement of said cylinders produced in response to a change in pressure as said first side of said gap passes said line of engagement during operation of said printing press, and stop means for opposing movement of said shock absorbing means to limit yielding thereof, said shock absorbing means including a resiliently yieldable means extend References Cited UNITED STATES PATENTS Ellis 101--40'7 Gurin 101-415.1

Abelmann 101401.2

Schacht 101-376 Frazier 101-4013 XR Neilson l01415.1 Stempel 101-2l7 Dietrich 101378 Norton et al. 101415.1 XR

Fagg 101-378 Bryer 10 1-375 Giori 101376 XR US. Cl. X.R. 

